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dcb_final_free: Router session is not closed anymore when dcb is closed. Router session is shared among all dcbs and is closed and freed with session. dcb_connect: dcb's state must be switched fro DCB_STATE_ALLOC to DCB_STATE_DISCONNECTED before dcb_final_free can be called for it. dcb_close: poll_remove_dcb encapsulates dcb's state transition in the same way as poll_add_dcb. Removed state modification from dcb_close. Read return value of poll_remove_dcb and log accordingly. dcb_set state: remove dassert if dcb_set_state_nomutex returned false. False can be returned indicating that intented change didn't occur but the end state, for example, may be acceptable. Failures in state transitions are asserted in dcb_Set_state_nomutex. poll.c poll_add_dcb: dcb state is now set here to either DCB_STATE_LISTENING or to DCB_STATE_POLLING according to dcb's role. Failures in state setting and in epoll_ctl are detected, logged and handled. poll_remove_dcb: Failures in state setting and epoll_ctl are detected, logged, and handled. mysql_client_server_protocol.h Removed macros MYSQL_FAILED_AUTHENTICATION & MYSQL_SUCCESFUL_AUTHENTICATION as they were not necessary and used with constant values 0 and 1 depending on the case. Renamed variable 'conn' to 'protocol' in cases where it meant protocol. mysql_backend.c gw_read_backend_event: In case when there was nothing to read or read failed, backend dcb is closed because situation is assumed to be such that backend server closed its side of the socket. Removed macros MYSQL_FAILED/SUCCESFUL_AUTHENTICATION gw_create_backend_connection: Assigned protocol with fd which is connected to backend. backend_write_delayqueue: In case where dcb_write fails to write anything, close backend dcb to avoid it getting hanging. mysql_client.c gw_read_client_event: Read return value of routeQuery and if it isn't == 1, call mysql_send_custom_error with client dcb and set client's protocol state to MYSQL_IDLE instead of MYSQL_ROUTING. gw_MySQLAccept: Static reply counter was erroneously used as a criteria for jumping to return point where return value was constantly 'success' (=0). Replaced static reply counter with private. Fixed return value in different cases. mysql_common.c gw_receive_backend_auth: Changed to return boolean values indicating of success or failue. Used integers which were assigned to macroed values on the caller side. Added length check before accessing buffer. readconnroute.c Cut too long lines and removed statements with side effects. skygw_debug.h Added macro STRPROTOCOLSTATE(s) to produce string representation of a given protocol state.
/** \mainpage MaxScale by SkySQL The SkySQL MaxScale is an intelligent proxy that allows forwarding of database statements to one or more database server user complex rules and a semantic understanding of the database satements and the roles of the various servers within the backend cluster of databases. The MaxScale is designed to provided load balancing and high avilability functionality transparantly to the applications. In addition it provides a highly scalable and flexibile architecture, with plugin components to support differnt protocols and routing decissions. The MaxScale is implemented in C and makes entensive use of the asynchronous I/O capabilities of the Linux operating system. The epoll system is used to provide the event driven framework for the input and output via sockets. The protocols are implemented as external shared object modules which can be loaded and runtime. These modules support a fixed interface, communicating the entries points via a structure consisting of a set of function pointers. This structured is called the "module object". The code that routes the queries to the database servers is also loaed as external shared objects and are referred to as routing modules. \section Building Building the MaxScale Edit the file build_gateway.inc in your skygateway directory and set the ROOT_PATH and MARIADB_SRC_PATH variables to the location in which you checked out the code and the location of your MariaDB source. Build the libmysqld in $MARIADB_SRC_PATH Go to the sky gateway directory and do a make depend to update all the dependency files and then do a make. This should get you all the things built that you need. Other make targets are available install - Installs the binary and the modules in the location defined by the make variable DEST ctags - Build tags files for the vi editor documentation - Build the doxygen documentation depend - Update the dependencies used by the makefiles Two files are required for the libmysqld library that is used within MaxScale, /usr/local/mysql/share/english/errmsg,sys and a my.cnf file with the following: [mysqld] max_connections=4096 \section Running Running the MaxScale The gateway consists of a core executable and a number of modules that implement the different protocols and routing algorithms. These modules are built as shared objects that are loaded on demand. In order for the gateway to find these modules it will search using a predescribed search path. The rules are: 1. Look in the current directory for the module 2. Look in $MAXSCALE_HOME/modules 3. Look in /usr/local/skysql/MaxScale/modules Configuration is read by default from the file $MAXSCALE_HOME/etc/MaxScale.cnf, /etc/MaxScale.cnf, an example file is included in the root of the source tree. The default location can be overriden by use of the -c flag on the command line. This should be immediately followed by the path to the configuration file. */